[ILUG] gcc and printf style functions

[kevin lyda]

i'm using the sqlite library for a project.  one way to execute sql
calls is to use this function:

    int sqlite_exec_printf(sqlite *db,
                           char *sqlfmt,
                           int (*xCallback)(void*,int,char**,char**),
                           void *pArg,
                           char **errmsg,
                           ...);

with gcc you can tell the compiler and it can let you know if there's
a problem when that function is called.  so if the sqlite.h proto type
for this function was defined with that attribute it would give those
warnings for it.

    int sqlite_exec_printf(sqlite *db,
                           char *sqlfmt,
                           int (*xCallback)(void*,int,char**,char**),
                           void *pArg,
                           char **errmsg,
                           ...)  __attribute__((format(printf, 2, 6)));

that says that this function has a format string that uses a printf
style.  the format string is the second arg; the args to it begin at arg
6.

however.  there's a flaw.  sqlite_exec_printf()'s sqlfmt string has two
additional % escapes: %q and %Q.  they're like %s except that they
escape the string for sql (%q) and enclose it in single quotes (%Q).

i've read through the gcc docs and as far as i can see, i'd need to
change gcc in order to support new % format codes.  am i missing
something?

kevin

-- 
kevin lyda ~ dems for torture: salazar(co/10) landrieu(la/08) pryor(ar/08)
kevin at ie.suberic.net ~ nelson(fl/06) nelson(ne/06) lieberman(ct/06) 2/2/04
  Those who refuse to raise their voices against something as clearly evil
  as torture are enablers, if not collaborators.  --Bob Herbert, 2/11/04